Molded-in composite bushings

Abstract

This invention is directed toward a fiber reinforced resin matrix composite article having fiber reinforced resin matrix bushings. These bushings are formed by tightly wrapping the fibers to form a plug having the fiber orientation from about ±20° to about ±60° to the central axis around which the fibers are wrapped. The plug is then snugly inserted into a hole which has been cut in the composite article such that the central axis of the plug is perpendicular to the fibers in the composite article. The entire composite article containing the plug is then cured and the plug is then drilled out forming the bushing.

We claim: 
     
       1. A method of making a fiber reinforced resin matrix composite article having a fiber reinforced resin matrix bushing comprising: preparing an uncured, resin impregnated fiber reinforced composite article having at least one connecting hole formed therein,   tightly wrapping uncured resin impregnated fibers around a central axis forming a plug, until the diameter of the plug is substantially the same as that of the formed hole in the uncured composite article,   the plug is then inserted into the formed hole of the composite such that the central axis around which the plug is wrapped is substantially perpendicular to the composite article fiber orientation,   the composite article containing the plug is then cured, and an attachment hole of the proper dimensions is then drilled into the plug forming the bushing, said bushing having at least one layer of fibers which are oriented about ±20° to about ±60° to the central axis of the bushing.   
     
     
       2. The method of claim 1 wherein the wrapping of the plug includes wrapping at least one outer layer of fibers oriented about 90° to the central axis onto the about ±20° to about ±60° oriented fibers.